SPID#: 37 In order to develop improved methods for semen preservation which do not require sophisticated technology and which will permit collection of semen samples from the wild if needed, we are presently assessing the effects of Antifreeze Protein (AFP) and Insulin- Transferrin-Selenium (ITS) on chimpanzee (Pan troglodytes) spermatozoa during an abbreviated freeze-thaw process. The AFP or ITS are added to the diluent of the semen sample at concentrations of 0, 1, 10 and 100 mg/ ml. The semen from each animal was processed independently prior to exposure to the AFP or ITS. The fresh semen samples were collected by artificial vagina, analyzed for sperm count, viability, and motility using computer assisted motion analysis (CAMA). CAMA was performed on these samples to determine the post-thaw motility characteristics. Semen was frozen at wet ice temperature (approx 0 deg C.) for up to 96 hours. The motility of sperm in the fresh semen sample of the AFP experimental group was 66.0 %. The addition of AFP in varied concentrations of 1,10, and 100 mg/ml resulted in a decline in themotility but a constancy in all four motility parameters. The 100 mg/ml treatment gave a 96% post-thaw sperm motility which was similar to that of the fresh sample. The other two concentrations resulted in a dramatic decline with approximately a 10% recovery of sperm motility. The motility of sperm in the fresh semen sample of the ITS experimental group was 88.5%. Cryopreservation accompanied with addition of ITS in concentrations of 1, 10, and 100 mg/ml resulted in a decline in motility as well as a decline in three of the four motility parameters. The Curvilinear Velocity, Linearity, and Straight Line Velocity declined from the original pre-freeze value but remained constant among the different concentrations of ITS. The Lateral Head Movement remained close to the pre-freeze value. A concentration of 100 mg/ml ITS gave no recovery of sperm motility. Best results were obtained after addition of 100 mg/ml AFP